nRF Connect SDK v1.2.0 Release Notes

nRF Connect SDK delivers reference software and supporting libraries for developing low-power wireless applications with Nordic Semiconductor products. It includes the MCUboot and the Zephyr RTOS open source projects, which are continuously integrated and re-distributed with the SDK.

nRF Connect SDK v1.2.0 supports product development with the nRF9160 Cellular IoT device. It contains reference applications, sample source code, and libraries for developing low-power wireless applications with nRF52 and nRF53 Series devices, though support for these devices is incomplete and not recommended for production.


  • Support for the new nRF5340 device

  • New Multi-Protocol Service Layer (Multiprotocol Service Layer), included in nrfxlib

  • NFC supporting the new TNEP protocol

  • New nRF9160 samples and libraries

  • General updates and bugfixes

Release tag

The release tag for the nRF Connect SDK manifest repository ( is v1.2.0. Check the west.yml file for the corresponding tags in the project repositories.

To use this release, check out the tag in the manifest repository and run west update. See Get the nRF Connect SDK code for more information.

Supported modem firmware

This version of the nRF Connect SDK supports the following modem firmware for cellular IoT applications:

  • mfw_nrf9160_1.1.1

Use the nRF Programmer app of nRF Connect for Desktop to update the modem firmware. See Updating the modem firmware for instructions.

Tested boards

The following boards have been used during testing of this release:

  • PCA10090 (nRF9160 DK)

  • PCA20035 (Thingy:91)

  • PCA10095 (nRF5340 PDK)

  • PCA10056 (nRF52840 Development Kit)

  • PCA10059 (nRF52840 Dongle)

  • PCA10040 (nRF52 Development Kit)

For the full list of supported devices and boards, see Supported Boards in the Zephyr documentation.

Required tools

In addition to the tools mentioned in Installing manually, the following tool versions are required to work with the nRF Connect SDK:



Download link



J-Link Software and Documentation Pack

nRF Command Line Tools


nRF Command Line Tools

nRF Connect for Desktop

v3.3.0 or later

nRF Connect for Desktop

dtc (Linux only)

v1.4.6 or later

Install the required tools


See Install the GNU Arm Embedded Toolchain

GNU Arm Embedded Toolchain

As IDE, we recommend to use SEGGER Embedded Studio (Nordic Edition) version 4.42a. It is available from the following platforms:

  • Windows x86

  • Windows x64

  • Mac OS x64

  • Linux x86

  • Linux x64


The following sections provide detailed lists of changes by component.


  • Added the following samples:

    • Cloud client - shows how to connect to and communicate with a cloud service using the generic cloud API.

    • nRF9160: HTTPS Client - shows how to provision a TLS certificate and connect to an HTTPS server.

    • nRF9160: Serial LTE modem - demonstrates sending AT commands between a host and a client device. The sample is an enhancement to the nRF9160: AT Client sample.

  • Added the following libraries:

    • AWS IoT - enables applications to connect to and exchange messages with the AWS IoT message broker. The library supports TLS-secured MQTT transmissions and firmware over-the-air upgrades.

    • Modem key management - provides functions to provision security credentials to the nRF9160 modem. The library replaces the nrf_inbuilt_key APIs from the BSD library.

    • China Telecom ZZHC library - implements the self-registration functionality that is required to connect to the China Telecom network.

    • SUPL client and SUPL client OS integration - integrates the externally hosted SUPL client library. This library implements A-GPS data downloading from a SUPL server.

Updated samples and applications

  • nRF9160: Asset Tracker:

    • Added functionality to configure high/low thresholds for sensor data, so that only data below/above the threshold is sent to the cloud.

    • Modified the command format to match the format that is used by nRF Connect for Cloud.

    • Implemented support for receiving modem AT commands from the cloud and returning the modem’s response.

    • Added functionality to configure the interval at which sensor data is sent to the cloud. This makes it possible to change the poll/send interval for environmental and light sensors from the terminal card in nRF connect for Cloud.

    • Replaced printk calls with calls to the Logging subsystem.

    • Added a separate workqueue for the application, instead of using the system workqueue.

  • nRF9160: GNSS:

Updated libraries

  • Download client:

    • Added the CONFIG_DOWNLOAD_CLIENT_MAX_TLS_FRAGMENT_SIZE option that allows to configure fragment sizes for TLS connections and non-TLS connections independently.

    • Added support for using non-default ports.

  • Secure Partition Manager (SPM):

    • Updated the security attribution to configure the peripherals NRF_REGULATORS and NRF_WDT as Non-secure.

    • Added the RTC0 peripheral (as Non-Secure).

    • Fixed a bug where the library attempted to set the IRQ target state of the P0 peripheral.

  • FOTA download:

    • Added an optional progress event (FOTA_DOWNLOAD_EVT_PROGRESS) that informs the user of the library how many bytes have been downloaded.

    • Fixed a bug where the library continued downloading even if writing to the DFU target failed.

    • Implemented a mechanism to retry downloads if a socket error occurs.


    • Added functionality to resume jobs that are marked as being in progress, which ensures a more robust FOTA operation through AWS IoT jobs.

    • Added offset reporting through the statusDetails field in an AWS IoT job, which makes it possible to track the progress of a FOTA operation more precisely.

    • Removed the unused app_version parameter from the aws_fota_init() function.

    • Inversed the interpretation of the return value of aws_fota_mqtt_evt_handler(). 0 now indicates success, and no further handling is required. 1 indicates that further processing is required by the mqtt_evt_handler() that called aws_fota_mqtt_evt_handler().

  • nRF Cloud:

    • Removed the button/switch pairing method.

    • Added functionality to handle the device configuration in the device shadow.

  • LwM2M carrier:

    • Updated to version 0.8.1.

  • at_host (lib/at_host):

    • Changed the default line ending from CR to LF in Kconfig to support sending SMS.

  • Moved the following libraries from drivers/ to lib/:

    • at_cmd library

    • lte_link_control

Updated drivers

  • Moved the following drivers from drivers/ to drivers/gps/:

    • gps_sim

    • nrf9160_gps

BSD library

  • Updated the BSD library to version 0.6.1.


This release demonstrates a dual-core solution with the Bluetooth LE Controller running on the network core and the Bluetooth Host and application running on the application core of the nRF5340.

Both Nordic Semiconductor’s nRF Bluetooth LE Controller and Zephyr’s Bluetooth LE Controller have been ported to run on the network core (nrf5340_dk_nrf5340_cpunet). The application core (nrf5340_dk_nrf5340_cpuapp) can run Bluetooth LE samples from both the nRF Connect SDK and Zephyr.

  • Added the following sample:

    • Radio test (short-range) - runs on the network core and demonstrates how to configure the radio in a specific mode and then test its performance. This sample was ported from the nRF5 SDK.

  • Added support for the nRF5340 PDK board (PCA10095) with board targets nrf5340_dk_nrf5340_cpunet and nrf5340_dk_nrf5340_cpuapp.

  • Updated nrfx to support nRF5340.

  • Added NFC support.

Common libraries, drivers, and samples

  • Added the following libraries:

Updated samples and applications

  • nRF Secure Immutable Bootloader:

    • Moved the provisioning data (slot sizes/addresses and public keys) to one-time programmable (OTP) memory for nRF9160 devices.

    • Implemented invalidation of public keys.

Updated libraries

  • Firmware information:

    • Renamed ABIs to EXT_APIs.

    • Restructured the fw_info structure:

      • Renamed the fields firmware_size, firmware_address, and firmware_version to size, address, and version.

      • Added a field to invalidate the structure.

      • Added reserved fields for future use.

      • EXT_APIs are now in a list at the end of the structure, instead of being available behind a function call.

      • EXT_APIs can now be requested by adding a request structure to a list after the EXT_API list itself.

    • Updated how EXT_API requests are checked. Requests are now checked against EXT_APIs by the bootloader before booting the image.

    • Added two new allowed offsets for the struct: 0x0 and 0x1000 bytes.

    • Removed memeq() in favor of regular memcmp().

    • Renamed __ext_api() to EXT_API(), because names starting with __ are reserved for the compiler.

    • Added new configuration options CONFIG_*_EXT_API_REQUIRED and CONFIG_*_EXT_API_ENABLED for, respectively, users and providers of EXT_APIs.

  • DFU target:

    • Added the configuration option CONFIG_DFU_TARGET_MCUBOOT_SAVE_PROGRESS, which uses Zephyr’s Settings subsystem. When this option is enabled, the write progress of an MCUboot style upgrade is stored, so that the progress is retained when the device reboots.

    • Fixed a bug where dfu_target_done() logged the error message unable to deinitialize dfu resource when no target was initialized.

  • Moved the following libraries from drivers/ to lib/:


nRF Bluetooth LE Controller

  • Updated the SoftDevice Controller libraries:

    • Removed version numbers for the libraries.

    • Added preliminary support for the S140 variant with the nRF5340 device. The Bluetooth LE Controller for nRF5340 supports the same feature set as its nRF52 Series counterpart.

    • Moved some APIs to Multiprotocol Service Layer. The library must now be linked together with MPSL.

    • Made Data Length Extensions a configurable feature.

    • Fixed an issue where an assert could occur when receiving a packet with a CRC error after performing a data length procedure on Coded PHY.

    For details, see the Changelog.

Multi-Protocol Service Layer (MPSL)

  • Updated the Multiprotocol Service Layer libraries:

    • Removed version numbers for the libraries.

    • Added a library version with preliminary support for the nRF5340 device. The feature set is the same as in the MPSL library for nRF52.

    For details, see the Changelog.


Bluetooth Low Energy


  • Added the following samples:

    • NFC: TNEP tag and NFC: TNEP poller - demonstrate how to use the Tag NDEF Exchange Protocol (TNEP).

    • NFC: System OFF - demonstrates how to wake the device from System OFF mode using NFC. This sample was ported from the nRF5 SDK.

  • Added the following libraries:

  • Updated the NFC samples to enable stack protection, assertions, and logging by default.

  • Extended the NFC: Tag reader sample with parsing and printing of the Type 4 Tag content.

  • Moved the NFC Platform implementation to the sdk-nrf repository. See Integration notes.

Multi-Protocol Service Layer (MPSL)

Setting storage

  • Reduced the default partition size for the settings storage from 24 kB (0x6000) to 8 kB (0x2000). This leaves more flash space to the application.

nRF Desktop

  • Added a ble_qos module to maintain channel maps.

Build system

  • Fixed a bug where a user-defined HEX file that was provided in the static configuration of the Partition Manager was not included in the merge operation.


  • Updated to v2.1.0. For details, see the changelog.


This release is based on Zephyr v2.1.99 (more precisely, Zephyr revision 40175fd3bd), which is between the upstream Zephyr v2.1 and v2.2 releases.

To see a comprehensive list of changes introduced since nRF Connect SDK v1.1.0, use the following Git command:

git log 7d7fed0d2b..40175fd3bd


  • Updated to include new features from upstream:

    • New downgrade prevention feature (available when the overwrite-based image update strategy is used)

    • New swap method that removes the need for a scratch partition

    • Bug fixes

    See the MCUboot release notes for more information. Note that not all features from v1.5.0 are included.


Known issues


  • The nrf_send() function in the BSD library might be blocking for several minutes, even if the socket is configured for non-blocking operation. The behavior depends on the cellular network connection.

  • The nRF9160: GNSS sample stops working if SUPL client and SUPL client OS integration support is enabled, but the SUPL host name cannot be resolved. As a workaround, insert a delay (k_sleep()) of a few seconds after the printf on line 294 in main.c.

  • The nRF9160: Asset Tracker sample might show up to 2.5 mA current consumption in idle mode with CONFIG_POWER_OPTIMIZATION_ENABLE=y.

  • The SEGGER Control Block cannot be found by automatic search by the RTT Viewer/Logger. As a workaround, set the RTT Control Block address to 0 and it will try to search from address 0 and upwards. If this does not work, look in the builddir/zephyr/ file to find the address of the _SEGGER_RTT symbol in the map file and use that as input to the viewer/logger.

  • nRF91 fails to receive large packets (over 4000 bytes).

  • nrf_connect fails if called immediately after initialization of the device. A delay of 1000 ms is required for this to work as intended.


Bluetooth Low Energy

  • Bluetooth LE cannot be used in a non-secure application, for example, an application built for the nrf5340_dk_nrf5340_cpuappns board. Use the nrf5340_dk_nrf5340_cpuapp board instead.

  • The Bluetooth: Peripheral HIDS keyboard sample cannot be used with the SoftDevice Controller because the NFC subsystem does not work with the controller library. The library uses the MPSL Clock driver, which does not provide an API for asynchronous clock operation. NFC requires this API to work correctly.

  • When the Bluetooth: Peripheral HIDS mouse sample is used with the Zephyr Bluetooth LE Controller, directed advertising does not time out and the regular advertising cannot be started.

  • The Bluetooth: Central HIDS sample cannot connect to a peripheral that uses directed advertising.

  • When running the Bluetooth: Central SMP Client sample, the CONFIG_BT_SMP configuration must be aligned between this sample and the Zephyr counterpart (SMP Server Sample). However, security is not enabled by default in the Zephyr sample.

  • The central samples (Bluetooth: Central UART, Bluetooth: Central HIDS) do not support any pairing methods with MITM protection.

  • On some operating systems, the nrf_desktop application is unable to reconnect to a host.


  • Building and programming the immutable bootloader (see Secure bootloader chain) is not supported in SEGGER Embedded Studio.

  • The immutable bootloader can only be used with the following boards:

    • nrf52840_pca10056

    • nrf9160_pca10090

    It does not work properly on nRF51 and nRF53.


  • The NFC: TNEP poller and NFC: Tag reader samples cannot be run on the nRF5340 PDK. There is an incorrect number of pins defined in the MDK files, and the pins required for NFC Reader ST25R3911B cannot be configured properly.

  • NFC tag samples are unstable when exhaustively tested (performing many repeated read and/or write operations). NFC tag data might be corrupted.

Build system

  • It is not possible to build and program Secure Partition Manager and the application individually.


  • In the BSD library, the GNSS sockets implementation is experimental.

MDK (part of nrfx)

  • For nRF5340, the pins P1.12 to P1.15 are unavailable due to an incorrect pin number definition in the MDK.


  • The MCUboot recovery feature using the USB interface does not work.

In addition to the known issues above, check the current issues in the official Zephyr repository, since these might apply to the nRF Connect SDK fork of the Zephyr repository as well. To get help and report issues that are not related to Zephyr but to the nRF Connect SDK, go to Nordic’s DevZone.